Liquid crystal alignment layers used in aligning liquid crystal molecules in a certain direction are being applied to various fields. As the liquid crystal alignment layer, a photo alignment layer has a surface treated by radiating light so that adjacent liquid crystal molecules are aligned. Generally, the photo alignment layer may be fabricated by irradiating a photosensitive material layer with light, for example, linearly polarized light to align the photosensitive material in a certain direction.
In order to irradiate the photo alignment layer with a linearly polarized light, various types of polarized ultraviolet light splitting elements may be used.
For example, a polarized ultraviolet light splitting element using aluminum is disclosed in the following Patent Literature 1.